This is how to install INPA. This is only compiled by me, the information is out there for those willing to look. The true credit goes out to other people on the internet, some who toiled away making a program so that it's easier for us normies.
You'll need to do things like open Device Manager, and copy files.
If you can't do this (read: are over 40), you should probably pony up and buy a bavarian technic cable: http://www.bavariantechnic.com/
Bavarian Technic is much easier for an end user to install and use, and comes with software and free automatic updates. It has the same functionality as INPA if you aren't going to code your car and are just after fault codes and advanced diagnostics equipment.
Step 1: Initialize the Cable
Plug in your cable to your computer.
Install any drivers that came with your cable, or try your luck with windows autodetecting it.
Step 2: Install the Software
These instructions (more or less) courtesy of impac4000, wheover he or she may be, probably courtesy of someone else before that. All we know is they're under 40, that's for sure.
Step 1 - Install to C:\ with all default settings. Don't touch anything, just click next and proceed when prompted.
Step 2 - Install to C:\ . At the end you'll be prompted to press any key. If it installed correctly it'll say so. Tell windows, it's good for nothing so it doesn't know.
Step 3 - Get your SP-Daten files. The most recent update today is August 2014.
Pick an E60 folder (one of these), and extract it to C:\
If you pick the torrent you're downloading the data for a lot of cars. You only need to extract the E60 folder.
NOTE: You will need to reset the permissions on "C:\E60\data\gdaten" as it's read only and it will cause the WinKFP update to fail. Right click, properties, uncheck read only and click ok, ok. (I just did this for all of the E60 folder. It was easier.)
Step 3: BMW Coding Tool
BMW Coding Tool can be found here: https://drive.google.com/file/d/0B05B-MobZUn8LXN3a...
If you can't get it there, you can always join the bmwcoding.com forums, where it will then avaiable for free download. Install it to wherever makes you happy. Probably a good time to make a shortcut, too.
Open BMW Coding Tool. Select the SP Source C:\E60 . Or whatever your chassis is.Then
update SP-Daten, then WinKFP. It will prompt for backup, click NO.
In Device Manager, right click your port, Properties -> Port Settings -> Advanced -> Latency Timer Set this to 1 msec. COM PORT should stay at COM1